Pressure sensors based on a MEMS technology may include capacitive structures and/or membranes which run in parallel to a chip front side. A downsizing or reduction of such pressure sensors represents a research and development challenge.
Pressure sensors having parallel detection structures occupy in particular up to more than 70% of the chip surface. In order to reduce the size of these detection structures, a reduction of corresponding layer thicknesses is in particular also necessary. However, a reduction of layer thickness in the corresponding membranes proves to be difficult, since a smaller membrane may have reduced sensitivity. The result of this may be, in particular, that such pressure sensors do not satisfy the sensitivity requirements of an ASIC or a similar evaluation circuit.
Furthermore, the membrane sizes or the structures of the pressure sensors must be varied specific to the application. The result of this is that complex and costly methods are necessary for pressure sensors having a broad application spectrum.
European Patent No. EP 0 515 416 B1 describes a method for manufacturing an integratable, capacitive pressure sensor.